Connect with us

Solar Energy

Seeing both sides of light collection

Published

on

Seeing both sides of light collection

Two types of materials are better than one when it comes to solar cells, as revealed by an international team that has tested a new combination of materials and architecture to improve solar-cell efficiency.

Silicon has long dominated as the premier material for solar cells, helped by its abundance as a raw material. However, perovskites, a class of hybrid organic-inorganic material, are a viable alternative due to their low-cost and large-scale manufacture and potentially higher performance. While still too unstable for full commercialization, they might become available to the market by 2022.

KAUST’s Michele De Bastiani and Stefaan De Wolf, working with colleagues in Canada, Germany and Italy, now show that a combination of the two is the best approach. By optimizing the material composition and the architecture of a “tandem” device, the team has achieved efficiencies beyond commercial silicon solar panels.

Sunlight, of course, comes directly from the sun, but illumination also comes from light reflecting off other surfaces, known as albedo. A device architecture that collects light from the back as well as from the front can utilize this source. “Our bifacial tandems exploit both direct sunlight and the albedo to generate electricity in a more efficient way than their conventional counterparts,” explains De Bastiani.

He and the team started with a simple silicon device structure that was textured top and bottom to enhance light collection. They then used a solution-processing method to deposit a thin perovskite layer on top. A transparent back electrode allowed light in while also allowing a current to flow out. The researchers tested five perovskite materials, each with a different chemical composition, to increase the absorption of incoming light. In this way, they were able to identify the perovskite that best matched the electronic properties of the silicon.

“A restriction of the tandem configuration is the limited current through the lower of the two subcells,” says De Bastiani. “We designed our tandem with a unique feature: the perovskite subcell generates more current than the silicon counterpart by stealing light that would be otherwise absorbed by the bottom subcell.”

The team tested their bifacial devices and compared the performance to similar monofacial devices in various outdoor settings with a range of albedos, such as, for example, bright sandstone or concrete. They found that, in all conditions, the bifacial configuration outperformed the monofacial one.

“We are now investigating the stability of the perovskite while also scaling up the technology to the module level,” says De Bastiani. “For this, we are looking for industrial partners and sponsors.”

Source link

Continue Reading
Click to comment

Leave a Reply

Solar Energy

Project receives funding for advanced solar-thermal research

Published

on

By

Project receives funding for advanced solar-thermal research


Project receives funding for advanced solar-thermal research

by Sophie Jenkins

London, UK (SPX) Apr 12, 2024






The University of Surrey, leading a collaboration with the University of Bristol and Northumbria University, has received a GBP 1.1 million grant from the Engineering and Physical Sciences Research Council (EPSRC) to develop solar-thermal devices. These devices aim to revolutionize the way we heat homes and generate power, differing from traditional solar cells by converting sunlight into heat for energy production.

The research focuses on creating surfaces that selectively absorb sunlight and emit heat through near-infrared radiation. This project leverages the combined expertise of the institutions in photonics, advanced materials, applied electromagnetics, and nanofabrication to address a global need for efficient solar energy utilization.



Professor Marian Florescu, Principal Investigator from Surrey, highlighted the importance of the project: “The sun provides an immense amount of energy daily, much more than we currently harness. By advancing these solar-absorbing surfaces, we aim to transform solar energy use into a sustainable powerhouse for our increasing energy needs.”



Goals of the project include developing high-temperature solar absorbers, enhancing the efficiency of solar-absorbing structures, and improving the management of heat generated from sunlight. Prototypes will be constructed to demonstrate these technologies.



Professor Marin Cryan, Co-Principal Investigator from the University of Bristol, explained their focus on thermionic solar cell technology, which uses concentrated sunlight to initiate electron emission for high-efficiency solar cells.



Dr. Daniel Ho, Co-Principal Investigator from Northumbria University, added: “Our university leads in thermophotovoltaic research, utilizing advanced thermal analysis techniques. We’re excited to contribute to groundbreaking developments in renewable energy.”


Related Links

University of Surrey

All About Solar Energy at SolarDaily.com





Source link

Continue Reading

Solar Energy

Improving Solar and Wind Power Integration in the U.S. Grid

Published

on

By

Improving Solar and Wind Power Integration in the U.S. Grid


Improving Solar and Wind Power Integration in the U.S. Grid

by Clarence Oxford

Los Angeles CA (SPX) Apr 11, 2024






The Midcontinent Independent System Operator manages a high-voltage electricity network spanning from Manitoba to Louisiana, serving 45 million users. This vast operation requires maintaining a balance between the energy generated and the demand across its regions.

The traditional reliance on coal and natural gas power plants is changing. For example, wind farms in Iowa now generate over 64% of the state’s electricity, and recent initiatives like the Alliant Energy Solar Farm at Iowa State University represent the shift towards renewable energy sources. These sources, however, introduce variability and uncertainty into grid management.



Zhaoyu Wang, a Northrop Grumman associate professor of electrical and computer engineering at Iowa State, emphasized, The power system seeks certainty which is challenging with unpredictable natural resources like sun and wind.



Wang is leading the MODERNISE project, aimed at modernizing grid operations. The U.S. Department of Energy has earmarked a $3 million grant over three years for this initiative, with an additional $1.1 million coming from project collaborators including Argonne National Laboratory and Siemens Corp.



The project, titled Modernizing Operation and Decision-Making Tools Enabling Resource Management in Stochastic Environment, involves developing computational tools that allow for better integration and management of renewable energy sources into the grid.



Jennifer M. Granholm, U.S. Secretary of Energy, supported this initiative stating that effective integration of renewable resources is essential for deploying clean energy. The project is part of a larger $34 million investment by the DOE to develop technologies that enhance grid reliability and efficiency.



By aggregating smaller renewable energy resources into larger operational blocks, MODERNISE aims to improve grid stability and predictability. Bai Cui, project co-leader and assistant professor at Iowa State, explained that this approach allows operators to manage grid operations more effectively by understanding and handling the uncertainties of renewable supply sources.



This initiative promises to make grid operations more adaptable and efficient, critical for accommodating the increasing reliance on renewable energy.


Related Links

Iowa State University

All About Solar Energy at SolarDaily.com





Source link

Continue Reading

Solar Energy

Quantum Material Achieves Up to 190% Efficiency in Solar Cells

Published

on

By

Quantum Material Achieves Up to 190% Efficiency in Solar Cells


Quantum Material Achieves Up to 190% Efficiency in Solar Cells

by Clarence Oxford

Los Angeles CA (SPX) Apr 11, 2024






Researchers from Lehigh University have developed a material that significantly enhances the efficiency of solar panels.

A prototype incorporating this material as the active layer in a solar cell displays an average photovoltaic absorption rate of 80%, a high rate of photoexcited carrier generation, and an external quantum efficiency (EQE) reaching up to 190%. This figure surpasses the theoretical Shockley-Queisser efficiency limit for silicon-based materials, advancing the field of quantum materials for photovoltaics.



This work signifies a major advance in sustainable energy solutions, according to Chinedu Ekuma, professor of physics at Lehigh. He and Lehigh doctoral student Srihari Kastuar recently published their findings in the journal Science Advances. Ekuma highlighted the innovative approaches that could soon redefine solar energy efficiency and accessibility.



The material’s significant efficiency improvement is largely due to its unique intermediate band states, which are energy levels within the material’s electronic structure that are ideally positioned for solar energy conversion.



These states have energy levels in the optimal subband gaps-energy ranges capable of efficiently absorbing sunlight and producing charge carriers-between 0.78 and 1.26 electron volts.



Moreover, the material excels in absorbing high levels in the infrared and visible regions of the electromagnetic spectrum.



In traditional solar cells, the maximum EQE is 100%, which corresponds to the generation and collection of one electron for each photon absorbed. However, newer materials and configurations can generate and collect more than one electron per high-energy photon, achieving an EQE over 100%.



Multiple Exciton Generation (MEG) materials, though not yet widely commercialized, show immense potential for enhancing solar power system efficiency. The Lehigh-developed material utilizes intermediate band states to capture photon energy typically lost in traditional cells, including energy lost through reflection and heat production.



The research team created this novel material using van der Waals gaps, atomically small spaces between layered two-dimensional materials, to confine molecules or ions. Specifically, they inserted zerovalent copper atoms between layers of germanium selenide (GeSe) and tin sulfide (SnS).



Ekuma developed the prototype based on extensive computer modeling that indicated the system’s theoretical potential. Its rapid response and enhanced efficiency strongly indicate the potential of Cu-intercalated GeSe/SnS as a quantum material for advanced photovoltaic applications, offering a path for efficiency improvements in solar energy conversion, he stated.



While the integration of this quantum material into existing solar energy systems requires further research, the techniques used to create these materials are already highly advanced, with scientists mastering precise methods for inserting atoms, ions, and molecules.



Research Report:Chemically Tuned Intermediate Band States in Atomically Thin CuxGeSe/SnS Quantum Material for Photovoltaic Applications


Related Links

Lehigh University

All About Solar Energy at SolarDaily.com





Source link

Continue Reading

Trending

Copyright © 2017 Zox News Theme. Theme by MVP Themes, powered by WordPress.